150 things about Canadian palaeo, part 6 – marine fossils #FossilFriday

Last week I introduced you to one of the most famous fossil sites in Canada, Dinosaur Provincial Park. Generally speaking when people think of Canadian fossils, they think of dinosaurs and the large creatures that roamed the land during the Mesozoic and are commonly found in Alberta and Saskatchewan. However, marine fossils are also common in Canada, including a a large number of marine vertebrates. A few of these examples, starting at 37/150 include:

37. Do you know what the official gemstone of Lethbridge, Alberta is? It’s not your traditional amethyst or diamond, it’s ammolite, a rare gemstone found in the Korite mines of Alberta. Ammolite is formed from the fossilised shells of ammonites, extinct cephalopods (the only invertebrate I’ll talk about in this post) like the modern Nautilus, which are under intense heat and pressure which causes this amazing colourful mineral to form. Gem quality ammolite is only found in the Bearpaw Formation, the youngest and only marine formation of the 3 geological formations found in Dinosaur Provincial Park. It is formed mostly from the ammonite Placenticeras.

Ammolite Placenticeras shell

38. The largest mosasaur on display in the world is that of Bruce the mosasaur, a Tylosaurus from Manitoba, on display at the Canadian Fossil Discovery Centre in Morden, Manitoba. Bruce is 13 m long, and stormed the seas during the Late Cretaceous, approximately 80 million years ago. Mosasaurs (a group of marine reptiles) are known as apex predators in the ocean, meaning Bruce was probably the top of the food chain when he was around. And you think sharks are scary!

39. Another group of extinct marine reptiles found in Canada is the plesiosaurs, which are primarily represented by long-necked animals called elasmosaurids, like AlbertonectesThese animals are known for their excessively long next, reaching up to 76 neck vertebrae in Albertonectes, which has the longest neck of all of them. Plesiosaurs have also been found in the oilsands of Alberta.

40. The Late Triassic Pardonet Formation of Williston Lake, BC is known for fossils of another kind of marine reptile, the ichthyosaurs. Ichthyosaurs evolved in the Early Triassic, and the group including those found in Williston Lake like Macgowania first appear in the Late Triassic, making these discoveries interesting in understanding their evolution.

41. Going back in time a bit more, we get the Late Devonian Bothriolepis canadensis from Quebec. This is a particularly great example of an antiarch placoderm (‘armoured fish’). Rather than having internal skeletons like most modern vertebrates, these fish had dermal skeletons that acted and looked somewhat like armour. Although there are several other species of BothriolepisB. canadensis is known for the large number of relatively complete, well-preserved specimens from Quebec.

External skeleton of Bothriolepis canadensis. Img from Smokeybjb.

42. And finally, back in time a little further is the the Man on the Hill (MOTH) locality of the Northwest Territories is an extremely important region dating back to the Early Devonian (approximately 418 million years ago). In particular, this locality is known for producing exquisite fish fossils, especially those of acanthodians, or ‘spiny sharks’. These specimens have helped to understand the evolution of this strange group.

There are plenty of other examples of marine fossils and localities, which I’ll discuss a bit more in future. Hope you enjoyed the first glance at Canadian marine fossils!

The series:

Part 1: Intro

Part 2: The Burgess Shale

Part 3: Early Canadian Palaeontologists

Part 4: Canadian Fossil Names

Part 5: Dinosaur Provincial Park

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